Android phone connecting to WiFi but says "no internet"

[BadAndy]

My internet is definitely connected because I'm using my WiFi connection on my laptop to ask this question.  My wife's (Android) phone is able to connect to the internet.

When I connect my phone to the WiFi I get an error saying that there is no internet.  When she originally connected some sort of website popup showed that she needed to sign in, but this is not happening for me.

What phone settings could be interfering with the ability to connect to the internet through the WiFi?

[BadAndy · Accepted solution]

Answering my own question so that if somebody encounters this in the future they can also try.

My problem was that I use a private DNS server to block adverts and malware.  Sky broadband wouldn't connect because of this.

[Sue104]

Hi, our phones are connected to the Internet (I have android and my son has an iPhone) but apps are saying no connection to Internet.  Without realising I have used up all of my mobile credit now because it took over as no connection 😒 please can  anyone help?